Hi All,

I was looking on the forum for a solution, but the solution I found seems to not work anymore in the current version of OutSystems so that's why I'm making a new post.

I am consuming a REST API that requires the following pattern: 

{URLofAPI}?Param1={valueParam1}&Param2={value1}&Param2={value2}&Param2={value3}

The problem I encountered was that if I manually defined a string in the value of Param2, it would be encoded by OutSystems, so it would look like this: "Param2={451}%26Param2%3d452" etc. I managed to solve it as follows:

I have added several same name parameters in the URL path of the API and some input matching that amount of same name parameters that will function as a maximum amount of duplicate parameters. It looks like this:

APIURL?Param1={valueParam1}&Param2 ={PARAM 2}&Param2 ={PARAM 3}&Param2 ={PARAM 4}&Param2 ={PARAM 5}

As you can see there are currently five parameters defined in the REST call which means that there is a maximum of five duplicate parameters you can pass. Then in the OnBeforeRequest you check the (if you have more parameters than the duplicate ones name and) value of the param to check if it is filled and if not you don't add it to the query parameter list of the customized request. The URL you specified before will force OutSystems to not encode the duplicate parameters because you predefined them in the URL path.